WALTHAM, Mass. — There are so many moments in Marcus Smart's life that have helped shape and define who he is as a player, that picking one or even one dozen, isn't easy.

For his mother Camellia Smart, there was one that stood out.

It was the shoving incident against Texas Tech last season which ultimately resulted in Smart being suspended three games and having his tough-guy reputation somewhat sullied by a momentary loss of composure in which he went too far.

She remembers how tough it was for her son to not be able to be with his team in battle, to be the leader that he has shown himself to be time and time again.

"It was a reminder for him," his mother told CSNNE.com, "That all your dreams, they can be gone ... just like that. It was a lesson he needed."

Indeed, Smart returned to action and was as focused a player as you could find in college basketball which is among the many reasons why the Celtics felt good about him being on the draft board when it was their turn to pick at No. 6.

Smart was projected to potentially be around for Boston at No. 6, but there were some rumors on the eve of the draft that he might go sooner than that if certain trades were made.

The attraction to Smart for the Celtics goes all the way back to one of the more popular Red Auerbach-isms which had to do with wanting a team with "instigators" on the roster; that is, guys that have a knack for getting under the skin of opponents.

For all the praise that Smart gets for his game, his ability to fluster opponents - particularly with his defense - is the kind of quality that the Celtics desperately need going forward as they continue to form the foundation for what they anticipate will be a better team than last season's club.

"I grew up being that type of person," Smart said. "I'm going to do whatever it takes to shut down my opponent. That's the person I am. I take a lot of pride (in that)."

And his mother takes a tremendous amount of pride in seeing how Smart has grown both as a player and as a person.

She will be the first to tell you that her son - like most sons and daughters and mothers and fathers - is far from perfect.

But he has dreams, dreams that he has hung to for years despite several hurdles and obstacles that could have easily derailed him into a life far removed from the NBA.

Dreams that even to his biggest fan, his mother, seemed too good to be true.

"I never dreamed Marcus would be in the NBA," she admitted. "But he told us (Camille and her husband) when he was nine years old, that when he got to the NBA he would retire us. We just laughed. We already retired. We get tickled knowing that this young man's dream came true."

And it's a dream that was deferred for a year when Smart decided to return to Oklahoma State as a sophomore when he would have likely been a high lottery pick - potentially the No. 1 overall selection - had he come out after his freshman season.

While his return to school didn't bolster his stock in terms of draft position, it did give teams another year to evaluate his game and for the Celtics, allowed them to land a player who could evolve into the kind of difference-maker they need.

His mother was not surprised that Marcus returned to school for a second year.

"He would call and talk to me and I would visit with him and I would tell him, 'this is a job,'" referring to the NBA. "Make sure you're ready but be a kid as long as you can. Because as you grow up, there's no going back.'"

There's little doubt in anyone's mind that Smart, both physically and mentally, is ready to play in the NBA.

He comes to the league with a life full of lessons learned, some as trivial as improving his shooting touch while others far more impactful like dealing with the death of a brother or coping with a fan that did to him what he usually does to opponents which is to get under their skin.

Smart doesn't speak about his mistakes in a pride-filled or boastful manner. But he knows without those mistakes, there would be no lessons learned.

And without those teachings, there's no telling if he would be where he's at now, in the NBA, living out the dream that he set for himself years ago.

It's a dream that has become reality, strengthened in part by a shoving incident involving a fan that at the time at least, raised many questions and concerns about his character and temperament.

"It helped him grow up, to have realized life, your dreams, they can be taken from you," she said. "Even on his home court, he couldn't go in the gym and watch them. He had to watch on TV in the dressing room. He realized this can be taken away from you. I tell him all the time, life is short so enjoy it. He does that now."

A. Sherrod Blakely serves as Comcast SportsNet's NBA Insider. Read more from Sherrod here, or follow him on Twitter or Facebook.